I am using Managed Property in my application, it's a custom column in my site collection, I could make a managed property and link this to the crawled property and everything is ok. Now in my application, I am returning data using xml like this: http://lh5.ggpht.com/-vRX9npffnMU/UOmVDkYNhuI/AAAAAAAAB1E/sWQ1uO4-mws/s1600-h/SearchRESTCallResults4.png and getting the exact property using: result.Cells.results.Value and so on.. but the managed property doesn't appear in the xml, and I don't know the index of this property. What should I do?
Try adding your custom managed property to the SelectProperties attribute in your Rest query against the search API.
Also make sure your Managed Property is marked as Retreivable in the search service application.
Microsoft has great documentation regarding using the search Rest API here: http://msdn.microsoft.com/en-us/library/office/jj163876.aspx